均匀化处理对6061铝合金棒材显微组织影响研究

Study of Homogenization Treatment on Microstructure of 6061 Aluminum Alloy Rod

应用金相显微镜和SEM研究了均匀化处理后6061铝合金的显微组织,结果表明铸态组织晶界上有较多的粗大析出相粒子。经过均匀化处理后,晶粒尺寸显著增加。存在的网状非平衡相和枝晶组织也已经基本回溶至铝基体内,晶界上的粗大析出相粒子数量有所减少。SEM分析表明,铸态中存在的析出相粒子是细长针状的Al(MnFe)Si相,经过均匀化处理后,针状Al(MnFe)Si相开始分段断裂,部分回溶至基体内,残留部分表现出球化特征。该类析出相粒子的存在有利于提高合金强度和塑性,提高了产品的后续加工性能。

Using metallographic microscope and SEM studied the microstructure of 6061 aluminum alloy after homogenization treatment.The results show that there are many coarse precipitate particles observed on the grain boundary of as-casted microstructure.After homogenization treatment,the grain size increases remarkably.The existing network non-equilibrium phase and dendritic structure dissolved back into the aluminum matrix substantially,and the amount of coarse precipitate particles on the grain boundary is reduced.SEM analysis shown that the precipitated phase particles in the as-casted alloy were slender needle-like Al(MnFe)Si phase.After homogenization treatment,the needle-like Al(MnFe)Si phase started to be broken and partially dissolved into the matrix,while the residual portion exhibited spheroidization characteristics.The existence of such precipitated phase particles is good to improve the strength and plasticity of the alloy and the subsequent processing ability of the product.